Black-line moist diazotype process



United States Patent 3,382,070 BLACK-LINE MOIST DIAZOTYPE PROCESS Walter J. Welch, Port Dickinson, N.Y., assignor to General Aniline & Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Jan. 2, 1964, Ser. No. 335,366 5 Claims. ((11. 96-4-9) ABSTRACT OF THE DISCLOSURE Process of moist developing a light-sensitive diazotype material to form a black 'azo dye image wherein the said material contains as the light-sensitive diazonium composition a mixture of a 2,5-dialkoxy-4-morpholino-1- benzene diazoniurn compound and a 3-alkoxy-4(N alkyl- N-benzylarnino) benzene diazonium compound.

The present invention relates to a novel combination of diazo structures having unusual and unique properties when combined, making them particularly adapted for use in the one-component or moist diazotype process to produce a dense black dye, and to novel light-sensitive compositions containing the same.

In considering candidate diazo materials for use in the commercial moist diazotype processes in use today to provide standard black-line photosensitive materials, consideration mustbe given to photosensitive materials which require the shortest exposure to a light source to create a latent image as Well as to the absorption spectrum of the photosensitive material being considered. These are important considerations since faster printing materials which at the same time yield images of higher density on a clean white background will find a ready place in the market. Diazos having certain ultraviolet light adsorption spectrum use more efiiciently the available light energy so less time is required for the photochemical reaction.

Many suggestions have been heretofore proposed to increase the speed of printing materials which at the same time provide images of higher density. One such proposal is concerned with the proposition of providing structural variations in light-sensitive diazos to increase the light sensitivity of the resultant material.

For instance, the Kalle PB Reports (PB 25781, 44231) describe several materials of this type corresponding to the general formula I la+ X" wherein R is ethyl and R can be methyl, ethyl, hydroxyethyl benzyl, and o-dichlorobenzyl, andX is an anion. These compounds can be found on pp. 369, 370,

375, 1202, 1245, 1335, 1336, 1345, 1347 and 1358 of these reports. These materials are reported to show somewhat increased light sensitivity over conventional p-phenylenediamine diazos.

3,382,070 Patented May 7, 1968 It is also known that certain of the compounds of US. Patent 2,298,444, especially those of the general strucwherein Z is a non-metallic element necessary to complete a morpholine nucleus, have unique diazotype prop erties. The most useful diazotype property has been the unusually high actinic opacity of dyes formed from such diazos which makes them of such value in formulating diazotype intermediate materials. However, these diazos exhibit certain characteristics which limit their use in the dazotype process. For example, they are fast coupling and thus can be used only with coupling components which react slowly to form a dye. In addition, they give purple dyes with couplers which normally form blues. This restricts their value considerably in that acceptable black-line sensitized materials are very difiicult to prepare.

When diazos of the formula t NJ \O R3 R0 lGf'X wherein R, Z and X are as above defined, are used with an alkaline moist developing formulation an undesirable purple black dye is often produced.

Similarly, when diazos of the formula wherein R and R represent alkyls, and X an anion, are used with an alkaline moist developing formula, a very brown-black dye results.

The object of this invention resides in the provision of moist 0r one-component diazo compositions which can be employed in formulating standard black-line photosensitive materials.

Other objects and advantages of the invention will become further apparent from the following detailed description of what is considered to be novel and inventive.

It has quite unexpectedly been discovered that in onecomponent or moist diazotype materials, valuable and unique properties, not singly possessed by light-sensitive diazos previously employed, are exhibited by the conjoint use of two diazonium compounds, one comprising a 2,5 dialkoxy 4 m'orpholino-l-benzenediazomum compound of the formula:

and the other a 3-alkoxy-4-(N-alkyl-N-benzylamino) benzene diazonium compound of the formula:

in which R and R are alkyl of from 1 to carbon atoms, i.e., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl or the like, and X is an anion or a double salt group.

These diazo compositions exhibit increased light senv sitivity compared to other diazos used singly or jointly, such as those of the above PB Reports. Most importantly, however, is the fact that said diazos when used jointly in moist black-line papers exhibit a synergistic effect leading, upon exposure and moist alkaline development, to intensely black images of excellent dye density.

The amounts of the diazos which can be employed in the sensitizing solutions to produce the moist black-line diazotypes are not narrowly critical and can be varied over a wide range. Generally, for each 100 cc. of coating solution from 0.5 to 1 gram of the 3-alkoxy-4-(N- alkyl-N-benzylamino)benzenediazonium compound is used as against 1 to 1.5 grams of the 2,5-dialkoxy-4- morpholinobenzenediazonium compound. These amounts are sufficient to impart the synergistic effect and achieve the desired results, although amounts above and below the above-prescribed range can be employed if desired.

Likewise, the amount of coupling component which can be employed in the developing solution is not narrowly critical. Generally, the couplers are added to the developing solution in amounts ranging from about .7 to about 2 grams per 100 cc. of developer solution.

Coatings containing the diazo compounds of the invention are appreciably more sensitive to mercury arc illumination as well as fluorescent illumination than conventional diazo materials. The coatings exhibit good stability both before and after development, develop well in the moist developer and produce black dye images of high density with good background.

The diazo compounds are generally employed in the form of their double salts with zinc chloride, stannic chloride, boron trifiuoride and the like. They are known compounds prepared by conventional methods.

Representative compounds within the scope of the above formulae include:

(1) 2,5 dimethoxy 4 morpholinobenzenediazonium chloride and the aforesaid double salts thereof;

(2) 2,5 diethoxy 4 morpholinobenzenediazonium chloride and the aforesaid double salts thereof;

(3) 2,5 dipropoxy 4 morpholinobenzenediazoniurn chloride and the aforesaid double salts thereof;

(4) 2,5 diisopropoxy 4 morpholinobenzenediazoni um chloride and the aforesaid double salts thereof;

(5) 2,5 dibutoxy 4 morpholinobenzenediazonium chloride and the aforesaid double salts thereof;

(6) 3 ethoxy 4 (N methyl-N-benzylamino)- benzenediazonium chloride and the aforesaid double salts thereof;

(7) 3 butoxy-4-(N-methyl-N-benzylamino)benzenediazonium chloride and the aforesaid double salts thereof;

(8) 3 methoxy-4-(N-ethyl-N-benzylamino)benzenediazonium chloride and the aforesaid double salts thereof;

(9) 3 ethoxy-4-(N-ethyl-N-benzylarnino)benzenediazonium chloride and the aforesaid double salts thereof;

(10) 3 ethoxy-4-(N propyl-N-benzylarnino)benzenediazonium chloride and the aforesaid double salts there of;

(ll) (3 methoxy-4-(N-butyl-N-benzylamino)benzenediazonium chloride and the aforesaid double salts thereof;

(12) 3 ethoxy-4-(N-butyl-N-benzylamino)benzenediazonium chloride and the aforesaid double salts thereof;

(13) 2 methoxy-4-morpholino-5-ethoxybenzenedia- :onium chloride and the aforesaid double salts thereof;

(14) 2 ethoxy-4-morpholino-5 propoxybenzenediazonium chloride and the aforesaid double salts thereof;

(l5) 2 butoxy-4-morpholino-5-ethoxybenzenediazonium chloride and the aforesaid double salts thereof;

16) 2 butoxy-4-morpholino-5-propoxybenzendiazoni um chloride and the aforesaid double salts thereof.

The moist alkaline developers are of the type usually employed in producing blackish images and, in this connection, reference is made to Kosaleks USP 2,822,272 dated Feb. 4, 1958 and particularly to Example III. These developers contain, as the coupler, phloroglucinol, but preferably mixtures thereof with resorcinol.

The coating solution, in addition to the light-sensitive diazo, may contain the various adjuncts usual in the manufacture of light-sensitive diazotype materials. These in clude metal salts for intensification of the dyestuff image, such as aluminum sulfate, nickel sulfate, zinc chloride and the like, stabilizing agents such as thiourea, naphthalene trisulfonic acid and the like; hygroscopic agents such as glycol, glycerin and the like; and wetting agents such as saponin, lauryl sulfonate, the oleic acid amide of N-methyl taurine and the like.

The base to which the coating solution is applied may be any of the bases which have been previously suggested for use in the diazotype field. Examples of such bases are high grade all-sulfite bond paper, rayon or cotton cloth, starch-filled cloth, partially hydrolyzed cellulose acetate filmbase, regenerated cellulose acetate and the like.

The invention will be more fully understood from the following examples which are illustrative only. The parts are by weight unless otherwise stated.

Example I A sensitizing solution is prepared as follows:

Grams Z-butoxy 4 morpholino-S-ethoxybenzenediazonium chlorozincate 1 3-ethoxy-4(N-ethyl-N-benzylarnino) The above sensitizing solution was coated on diazotype paper, dried and exposed to light under a translucent original and developed using the following alkaline solution:

A dense black dye is formed. This dye is very superior in color to that obtained when using either diazo alone, as shown by the following comparisons. In addition, it is very superior in density to the dye obtained from the use of a standard moist process diazo as described below.

Comparison tests with Example I The above sensitizing solution was coated on diazotype paper, dried, and exposed to light under a translucent original and developed using the following alkaline solution:

Grams Borax 50.0 Sodium carbonate 20.0

Thiourea 10.0

Phloroglucinol 8.0 Resorcinol 6.0 Sodium salt of isop-ropylnaphthalene sulfonic acid 2.0

Water, 1.0 liter.

A dense purple black dye is formed. A sensitizing solution similar to the one above containing a conventional diazo such as 4-(N-ethyl'N-benzylamino)benzenediazonium chlorozincate in an amount to achieve the same printing speed produces a neutral black dye of much inferior density.

B A sensitizing solution is prepared as follows:

Grams 3 ethoxy 4-(N-ethyLN-benzylamino)benzenediazonium chlorozincate 1.0 Citric acid 0.5 Aluminum sulfate 0.5 1,3,6-naphthalene trisulfonic acid 2.0 Thiourea 0.5 Modified corn starch (USP 2,328,537) 15.0 Silica 1.0 Polyvinylacetatc emulsion 3.0 Water 1000.0

The above sensitizing solution was coated on diazotype paper, dried, and exposed to light under a translucent original and developed using the following alkaline solution:

Grams Borax 50 Sodium carbonate 20 Thiourea 10 Phloroglucinol 8 Resorcinol 6 Sodium salt of isopropylnaphthalene sulfonic acid 2 Water A dense brown-black dye is formed. A sensitizing solution similar to the one above containing a standard moist process diazo such as 4-(N-ethyl-N-benzylamino)benzenediazonium chlorozincate in an amount to achieve the same printing speed produces a neutral black dye of much interior density.

Example II Using the following combinations of diazo structures in place of the 2butoxy-4-morpholino-5-ethoxybenzenediazonium chlorozincate and 3-ethoxy-4-(N-ethyl-N-benzlyamino)benzenediazonium chlorozincate and proceeding as in Example I gave similar results:

(a) 2,5 dimethoxy 4morpholinobenzenediazonium chloride and 3-rnethoxy-4-(N-methyLN-benzylamino)benzenediazonium chloride;

(b) 2,S-dieth0xy-4-morpholinobenzene diazonium chloride and 3-ethoxy-4-(N-methyl-N-benzylamino)benzenediazonium chloride:

(c) 2,5 dipropoxy 4-morpholinobenzenediazonium chloride and 3 propoxy 4-(N-methyl-N-benzylamino) benzenediazonium chloride;

(d) 2,5 diisopropoxy-4-morpholinobenzenediazonium chloride and 3-butoxy-4-(N-methyl-N-benzylamino)benzenediazonium chloride;

(e) 2,5-dibutoxy-4-morpholinobenzenediazonium chloride and 3-methoxy-4-(N-ethyl-N-benzylamino)benzenediazoniurn chloride;

(f) 2,5 diisobutoxy 4-morpholinobenzenediazonium chloride and 3 ethoxy 4-(N-ethyl-N-benzylamino)benzenediazonium chloride;

(g) 2,5 diamyloxy 4-rnorpholinobenzenediazonium chloride and 3-propoxy-4-(N-ethyl-N-benzylamino)ben- Zenediazonium chloride;

(h) Z-methoxy-4-morpholino-5ethoxybenzenediazonium chloride and 3 butoxy-4-(N-ethyl-N-benzylamino) benzenediazonium chloride;

(i) 2 ethoxy 4-morpholino-5-propoxybenzenediazonium chloride and 3-methoxy-4-(N-propyl-N-benzylamino benzen ediazonium chloride.

While the invention has been described with particularity and exemplified by way of specific examples to illustrate the same, it is obvious that variations and modifications thereof will become immediately apparent to those skilled in the art upon reading the same. Therefore, it is intended that all such modifications and variations be included within the scope of the invention as set forth in the appended claims.

What is claimed is:

1. The process of producing intense black azo images of high density which comprises exposing under a pattern a moist, black line, light sensitive diazotype material containing as the light sensitive diazonium compounds a mixture of a compound of the formula:

O N- NZ+X" OHF-GQ b OR with a compound of the formula CH5UII2 wherein R and R are alkyl of one through carbon atoms and X is an anion; and, developing the exposed material in a moist alkaline developer containing phloroglucinol as a coupler.

2. The method of claim 1 wherein the developer contains a mixture of phloroglucinol and resorcinol as the couplers.

3. A process as defined in claim 1 wherein the lightsensitive diazonium compounds are 2,5-diethoxy-4-morpholino-benzenediazonium chlorozincate and 3-ethoxy-4- (N-methyl-N-benzylamino) benzenediazonium chlorozincate.

4. A process as defined in claim 1 wherein the lightsensit-ive diazoniurn compounds are 2-butoxy-4-morpholinobenzenediazonium chlorozincate and 3-etl1oxy-4- (N-methyl-N-benzylamino) benzenediazonium chlorozincate.

5. A process as defined in claim 1 in which the lightsensitive diazoniurn compounds are 2-but0xy-4-morpholino-S-ethoxybenzenediazonium chlorozincate and 3- ethoXy-4-(N-ethyl N benzylamino)henzenediazonium chlorozincate.

References Cited UNITED STATES PATENTS 3,164,469 1/1965 Behmenburg et a1 96-91 2,793,118 5/1957 Sanders et a1 96-75 X 3,016,298 1/196-2 Sanders et al 96-75 3,028,240 4/1962 Werner et a1 96-91 3,064,049 11/1962 Cox 96-91 X 3,069,268 12/1962 Herreck 96-75 X 3,081,166 3/1963 Van Loon et al 96-91 X 3,123,472 3/1964 Wilders et a1. 96-91 X OTHER REFERENCES Benbrook, C. H., Trnerican Documentation, vol. 8, The Diazotype Process, pp. 86 relied on.

NORMAN G. TORCHIN, Primary Examiner.

I. TRAVIS BROWN, Examiner. 

